Method for forming plastic molded panels with inserts

ABSTRACT

Plastic panels which are useful as automotive interior trim panels, interior door panels and the like decorative and structural panels, are made by a method which integrates insert sections in the surfaces of the panels and eliminates insert edge trim molding strips. The method includes positioning inserts into a mold, adding plastic to the mold to form a thin plastic sheet, presized blank, then removing the plastic sheet portions with the inserts; next, positioning the blank in a mold against a mold face and molding in situ and simultaneously bonding a plastic substrate against the blank and the exposed surface of the insert. Alternatively the blank can remain in the same mold and a suitable mating half of the mold can close off the plastic sheet and the plastic substrate can be injected or poured into the mold.

BACKGROUND OF THE INVENTION

This invention relates to a composite, molded panel which may be shapedto form an interior door panel or an interior trim panel for a vehicleor to form similar types of panels used for other purposes. It isespecially useful in producing vehicle interior door and trim panelshaving decorative inserts which differ in appearance and compositionfrom other portions of the surfaces of the panels.

Interior door panels for vehicles are typically made by first forming apreselected size and shape foundation board made of stiff particleboard, fiber board, or plastic board-like material. Then, one or morecloth-like sheets are fastened to the surface of the board. The boardmay also function to support other items, such as window regulatorparts, small motors, wiring and the like, which are located upon orwithin the door. In many vehicles, the interior surfaces of the doorpanels are decoratively enhanced by adding inserts upon the panel. Theinserts may be in the form of smaller sections or panels which may beformed, for example, of carpet-like sheets or sheets with heavilytextured surfaces or sheets of different surface colors or material.Ordinarily, the joint line that appears around each of these inserts isa high frequency welt line or a fabricated trim strip which overlaps andconceals the raw edges of the insert and helps maintain the insert inplace. In many cases it is often a fabricated separately trimmed partwhich is in some way fastened to the foundation of the door itself.

Typically, the interior door and trim panels of the type describedabove, are assembled out of separate parts which are positioned upon thefoundation board and fastened together, one by one, to provide acomplete panel assembly. This assembly is fastened within the metal orplastic door or within other parts of the interior of the vehicle. Thistechnique for manufacturing interior door and trim panels is relativelytime-consuming and expensive. Moreover, this limits the ability tosignificantly contour or curve the interior surfaces of the vehicle. Forexample, it is difficult to provide a curved or contoured foundationboard and to cover such a curved board. Therefore, vehicle interior doorsurfaces are relatively flat and other trim surfaces are also of limitedcurvature.

Thus, this invention relates to a plastic molding method for makinginterior door and trim panels and the like, which may be curved, andwhich have different inserts molded in place, at reduced costs and withenhanced decorative appearances.

SUMMARY OF INVENTION

The invention herein contemplates molding a plastic panel by, first,preparing a thin, flexible plastic sheet which is sized and shaped toform a blank which sheet-like inserts of various types may be mounted.The inserts are either integrally formed with the sheet or bonded alongtheir edges to the sheet. The blank, with the inserts, is either formedor positioned within a mold. Next, plastic molding material is placedwithin the mold and is molded in situ to form a relatively rigid plasticmolded substrate whose exposed, outer surface is made up of thecomposite of the plastic sheet blank and the inserts of differentmaterials and textures which are carried by the blank.

Since the substrate is molded in situ within the thin plastic sheetblank, other objects may be simultaneously molded upon or within thesubstrate. For example, window parts, wires, drain tubes and the likemay be molded within the substrate. Alternatively, the substrate may beprovided with integral portions that are configured to receive or tomount exterior mechanical parts or trim elements. Thus, this method mayeconomically produce, for example, an interior door panel which may havecurved portions and which carries separately mounted or integrallyformed arm rests or window controls or other items mounted thereon,while providing an enhanced decorative appearance.

A major object of this invention is to provide a method which producespanels that have inserts of different textures or types of materials fordecorative enhancement, but wherein the normal edge trim molding whichhas been required in the past to conceal and protect the edges of theinserts may be completely eliminated.

Still a further object of this invention is to provide a method forrapidly and economically producing vehicle door panels and interior trimpanels and the like with a minimum of labor and with better, moreuniform quality than has previously been possible utilizing the typicalpanel assembly techniques which have been used in the past for makingdoor interior panels and trim panels.

Furthermore, it is the objective of this invention to manufacture thetrim face without the use of a converted PVC although PVC can be used,but instead by creating the outer exposed skin of the panel by the useof polyurea polymers in either spray or closed mold techniques.

These and other objects and advantages of this invention will becomeapparent upon reading the following description, of which the attacheddrawings form a part.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an automobile interior door panel whichschematically illustrates a panel made in accordance with the methoddescribed herein.

FIG. 2 is a perspective, schematic view illustrating the placement ofinserts into a mold.

FIG. 3 is a perspective, schematic view illustrating spraying theelastomer into the mold.

FIG. 4 is a perspective of a blank with the inserts.

FIG. 5 is a cross section view of FIG. 4 through line 5--5 thereof.

FIG. 6 is a cross section view of a mold in another embodiment used toform the blank.

FIG. 7 is a cross section view of a mold pair for adding the substrateto the blank.

FIG. 8 is a schematic, cross-sectional illustration of a female, vacuumforming mold with a blank positioned above it.

FIG. 9 is a schematic, fragmentary section of the vacuum mold of FIG. 7,showing insert edge receiving grooves.

FIG. 10 is a schematic illustration of the mold closed by an oppositemold half so as to provide the complete molding cavity.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates an example of an interior door panel 10for an automobile. The panel 10 is illustrated as being formed withcurved opposite ends. It is sized and shaped to fit within a sheet metaldoor for trimming the interior of the door within the passengercompartment of a vehicle. The panel includes, for illustration purposes,an upper panel insert 11 which may have an interior face formed so as tosimulate a wood grain appearance or may be an inlay of some othermaterial. Similarly, a lower insert 12 is positioned in the panel andmay be formed of a pile, carpet-like material, to simulate a carpetedsection of the panel or may be an inlay of some other material.

The panel may be provided with various openings or receptacle areas,after the molding is completed, to receive some of the hardware which istypically mounted within a vehicle door. These openings or areas may becut or punched in the panel. For example, the panel may have a square oroblong opening 13 to receive a block of switches which operate thewindow actuating motors, and a round opening 14 which may receive aswitch for actuating the exterior side view mirrors. Different size andshape openings and receptacle areas may be molded in the panel asrequired.

The interior surface 15 of the panel may be formed with embossments ormay be textured. These decorative surface configurations may be formedduring the molding of the panel door or may be preformed in the sheet orblank utilized in the molding.

The molding process involves starting with a mold 16 to form a sheet ofdesirable size to provide a blank 18 for molding purposes. The mold 16includes cavities 17 to enable positioning of the upper and lowerinserts 11 and 12 into the molding. The inserts 11 and 12 are positionedinto the mold cavities face down such that their finished surfaces gointo the mold cavity 17. A plastic polyurea elastomer is sprayed ontothe mold 16 as illustrated in FIG. 3. The polyurethane elastomer isquick curing and bonds to the upper and lower inserts 11 and 12.Preferably, the polyurea elastomers are formed by Jeffamine polyetheramine and isocyanates. Also a suitable self skinning type polyurethanemay also be used. The mold 16 may be treated with a desired releasingagent if required so that the blank may easily be peeled from the moldand be ready for use in the process. The sheet or blank 18 can be formedto a desired thickness and have desired characteristics. The sheet canbe provided with resilient capabilities and provide the desired feel ortouch. Alternatively, the mold may include an upper half 19 with anentrance aperture enabling the polyurea elastomer or self skinningpolyurethane to be poured or injected into the mold to bond with theupper and lower inserts. This is illustrated in FIG. 6.

In another embodiment of the invention, if it is desirable to remove theportion of the blank behind the inserts, the insert itself may be coatedwith a release layer and upon curing, the blank may be cut away in thearea of the insert to remove the underlining blank portion.Alternatively, the spray process can be computer controlled such thatthe back of the insert area, if required, is not sprayed. The removal ofthe underlining blank portion of the sheet which overlaps the insertpermits the insert to be arranged substantially coplanar with the sheetand exposes the insert face within a window-like opening in the sheet.Also, the spray may be controlled such that there is an overlap withoutthe blank covering the entire insert.

Next, the blank, in the mold, would be rotated to a second position. Atthat position, if necessary, wiring, switches, or the like would bepositioned onto the blank. If such a positioning of elements is notnecessary, the blank would move to another position. At this position, amale mold 30 is mated within the female mold 16' as seen in FIG. 7. Themale mold 30 fits into the female mold 16' such that there is a gap 32between the blank 18 and the male mold 30. The male mold 30 alsoincludes a bore 34 to enable passage of the substrate. If a second layerof less dense foam backing is required, it could be added prior to thesubstrate either by injection through the male mold or by spraying ontothe blank.

A suitable plastic material is injected into the mold cavity 32 forinjection molding the panel substrate 40 therein. The injected plasticmaterial solidifies in the cavity 32. Alternatively, expandable plasticbeads may be inserted into the mold's cavity, either through passageway34 or may be placed in the cavity before the mold is closed. Theapplication of suitable heat for the necessary time causes theexpandable beads to mold the substrate and seal it within the cavity.After the plastic solidifies, the mold panel 10 is removed. The moldpanel substrate 40 may include integral parts such as the molded bracket46, boss 47 and other separate parts positioned in the interior of themold cavity. Passageways or openings or receptacles may also be formedin the panel during molding. By way of an example, an electric motor foroperating the window, or part of a window regulator mechanism or wiresor switches or drain tubing used for draining water collected within thedoor or the like may be positioned in the panel during molding, aspreviously stated.

The blank may be placed within a female, vacuum mold 25 which isschematically shown in FIG. 8. This mold includes a molding cavity 26and grooves 27 which are formed in the cavity surface corresponding tothe preformed blank.

The vacuum mold 25 has a vacuum chamber 60 formed beneath it, with ahose 29 connected to a vacuum pump (not shown). Numerous holes 62 extendthrough the mold from the vacuum chamber to the mold cavity surface. Airis sucked from the cavity surface to the vacuum chamber for positioningthe blank on the mold cavity.

Then, as illustrated in FIG. 10, an upper, female mold half 37 ispositioned to close the mold cavity 38 for molding the panel substrate40 upon the molded blank.

The upper mold half 37 may include sub-cavity portions for moldinginterior parts integrally with the substrate. For example, a sub-cavityportion 41 may be provided for molding a bracket and another sub-cavityportion 42 may be provided for molding a ring or an enlarged boss. Inaddition, the upper mold half may include a suitable passageway 45through which plastic may be injected or otherwise placed within themold cavity.

When the mold is closed, a suitable plastic material may be injectedinto the mold cavity for injection molding the panel substrate 40therein. The injected plastic material solidifies in the cavity.Alternatively, expandable plastic beads may be inserted in the moldcavity, either through the passageway 45 or they may be placed in thecavity before the mold is closed. The application of suitable heat forthe necessary time causes the expandable beads to mold the substrate insitu within the cavity. After the plastic solidifies the mold panel 10is removed therefrom.

The molded panel substrate 40 may include integral parts, such as themolded bracket 46, boss 47, and other separate parts positioned in theinterior of the mold cavity. Passageways or openings or receptacles alsomay be formed in the panel during molding. By way of example, anelectric motor for operating the window, or part of the window regulatormechanism or wires or switches or drain tubing used for draining watercollected within a door, or the like may be positioned in the panelduring molding.

The methods described above are particularly useful for molding doorpanels and, thereby, replacing conventional door panel assemblies whichare made up of a number of parts that are fastened together. However,the methods are also useful in forming other types of trim panels forvehicles as well as other types of panels for other uses. For example,an interior dashboard panel may be formed with inserts of various typesmolded in the surface of the panel. As another example, a moldedheadliner may be formed for use within the upper part of the passengercompartment of a vehicle. Inserts of various kinds may be positioned inthe headliner panel. These inserts can be formed of a sound proofingmaterial or of a decorative carpet-like material, etc.

The molding methods are useful for producing panels made of a widevariety of materials. By way of example, the panel substrate may beformed of a substantially rigid, structural polyurethane plastic whichis commercially available from various chemical companies. Theparticular plastic selected will depend upon the cost, availability, andultimate use. Various commercially available insert materials, such aspile-like carpet, woven fabric materials or the like can be used for theinserts. The molding can be performed in a suitable, commerciallyavailable molding machine.

The overall molded plastic panel is waterproof. Therefore, conventionalwater shields that typically are utilized within vehicle doors, forprotecting the trim panel from water seepage due to water entering intothe door cavity, are unnecessary and eliminated. This reduces the costof the overall door assembly considerably.

This invention may be further developed within the scope of thefollowing claims.

Having fully described an operative embodiment of this invention, I nowclaim:
 1. A method for forming molded plastic panels having inserts, foruse as trim panels, interior door panels and the like, comprising thesteps of:(a) positioning an insert into a first mold; (b) adding apolyurea elastomer material into said mold; (c) forming a thin,flexible, polyurea sheet, from said polyurea elastomer material, of apredetermined size and shape such that said insert is secured to saidpolyurea sheet to provide a blank having an outer surface adjacent saidfirst mold and an inner surface on an opposite side of said blank; (d)positioning a mating mold adjacent said first mold and forming a cavitybetween said mating mold and said blank; (e) applying and bonding arelatively thick plastic substrate against the inner surface of theblank for bonding together surfaces of the blank and substrate; (f)thereafter, removing the molded panel from the mold to provide acomposite plastic panel having an exposed exterior surface formed ofouter surfaces of the blank and the insert; and (g) removing a portionof the sheet, which forms the blank, that overlaps the insert beforebonding the substrate to the blank so as to simultaneously bond an innerface of the insert directly to the substrate.
 2. A method for formingmolded plastic panels as defined in claim 1, including closing the moldbefore forming the plastic substrate and then, injection molding plasticwithin the mold to form the substrate within the mold cavity.
 3. Amethod for forming molded plastic panels as defined in claim 1, andincluding placing expandable plastic beads in the mold and closing themold and thereafter, expanding the beads for in situ molding of a foamedplastic substrate within the mold cavity.
 4. A method for forming moldedplastic panels as defined in claim 1, and including molding thesubstrate out of a substantially rigid polyurethane plastic material. 5.A method for forming molded plastic panels as defined in claim 1,including injecting said polyurea elastomer material into said mold toform said blank.
 6. A method of forming molded plastic panels as definedin claim 1, including pouring the said polyurea elastomer material intothe said mold to form said blank.
 7. A method for forming molded plasticpanels, having inserts, for use as trim panels, interior door panels andthe like, comprising the steps of:(a) positioning an insert into a firstmold; (b) adding a polyurea elastomer material into said mold; (c)forming a thin, flexible, polyurea sheet, from said polyurea elastomermaterial, of a predetermined size and shape such that said insert issecured to said polyurea sheet to provide a blank having an outersurface adjacent said first mold and an inner surface on an oppositeside of said blank; (d) removing said blank from said first mold; (e)positioning said blank in a second mold such that said blank outersurface is adjacent said second mold; (f) positioning a mating moldadjacent said second mold and forming a cavity between said mating moldand said blank; (g) applying and bonding a relatively thick plasticsubstrate against the inner surface of the blank for bonding togethersurfaces of the blank and substrate; (h) thereafter, removing the moldedpanel from the mold to provide a composite plastic panel having anexposed exterior surface formed of the outer surfaces of the blank andthe insert.